The present invention relates to constant velocity joints and more particularly, concerns constant velocity joints of the counter track type.
Constant velocity fixed ball joints in the form of a counter track joint, having an outer joint part with outer tracks, an inner joint part with inner tracks, torque transmitting balls which are received in pairs of tracks consisting of outer tracks and inner tracks, and a ball cage with cage windows in which the balls are held in a common plane and are guided on to the angle-bisecting plane when the joint is articulated are such joints, in which first outer tracks, together with first inner tracks, form first pairs of tracks whose control angles open in a first axial direction R1 and in which tracks first balls are held and in which second outer tracks, together with second inner tracks, form second pairs of tracks whose control angles open in a second axial direction R2 and in which tracks second balls are held. The control angles are defined as angles between the tangents at the ball contact points in the tracks.
With constant velocity fixed ball joints of this type, provision is generally made for the outer face of the cage and/or the inner face of the cage be approximately spherical in shape for the purpose of being supported relative to the outer joint part and/or the inner joint part. Such joints are described in DE 40 31 819 C1 and DE 40 42 390 C2 for example. Before such joints are assembled, the outer joint part is first broken into two halves which, after assembly, are held together by a sleeve.
Machining the outer joint part and the cage, which is in the form of spherical portions, is very complicated, and the same applies to the assembly operation.
It would therefore be desirable to provide a joint of the foregoing type which permits a simplified type of machining and assembly.
A constant velocity fixed ball joint having improved assembly and simplified manufacturability is provided. In the constant velocity fixed ball joint disclosed, the outer joint part, on its inside, forms a stop-and-guiding face for a spherical outer face of the ball cage. The stop-and-guiding face is undercut-free if viewed in the second axial direction R2. Furthermore, the ball cage, on its inside, forms a stop-and-guiding face for a spherical outer face of the inner joint part. This stop-and-guiding face is undercut-free if viewed in a first axial direction R1.
In one embodiment, in the first axial direction R1, the ball cage, by way of its cage windows, is supported on the second balls held in the second outer tracks and in the second inner tracks. Also, in the second axial direction R2, the inner joint part, by way of its second inner tracks, is supported on the second balls axially held in the cage windows of the ball cage.
The disclosed joint is particularly advantageous in that the cage, as a result of being undercut-free in its interior, is easy to produce. For example, the cage can be manufactured by non-cutting forming, using a punch. In addition, the guiding faces in the outer joint part for the ball cage are undercut-free, which, at least as far as the guiding face in the outer joint part is concerned, allows a simplified method of production by a non-chip producing forming operation. According to another embodiment, to the extent that at least part of the tracks are undercut-free, it is advantageous for the undercut-free tracks in the outer joint part to be arranged in the same direction as the undercut-free stop-and-guiding face for the ball cage, so that a substantial part of the inner surface of the outer joint part can be produced with a one-piece inner punch by a non-chip producing forming operation.
The characteristics of the present joint permit a largely simplified joint assembly. Thus, the ball cage with one half of the balls having been inserted, and the inner joint part, can be slid in as a preassembled group in a coaxial position into the outer joint part. The half of inserted balls refers to the first balls held in the first outer tracks and in the first inner tracks. For mounting the second balls held in the second outer tracks and in the second inner tracks, the usual method of over-articulating the joint and of individually inserting the second balls from the outside into the cage windows projecting from the outer joint part is employed. After all of the balls have been mounted, the joint is axially fixed without requiring any additional structures.
Other advantages of the invention will become apparent upon reading the following detailed description and appended claims, and upon reference to the accompanying drawings.